1. Field of the Invention
This invention relates to the field of integrated circuits. More particularly, this invention relates to the transfer of data values between different devices within an integrated circuit.
2. Description of the Prior Art
It is known to provide integrated circuits including multiple devices between which data must be transferred. As an example, an integrated circuit may include a processor and a memory between which data values must be transferred. On-chip communication circuitry, such as broadcast busses and point-to-point interconnects are known to provide for this inter-device communication.
Different communication protocols can be used on-chip. Some communication protocols are targeted at providing high bandwidth. Other communication protocols are targeted at providing low power consumption. An example of such on-chip bus protocols are those used within the AXI interconnect architecture designed by ARM Ltd of Cambridge, England.
There is also an increasing trend within the field of integrated circuits to provide a larger number of devices on a single integrated circuit. These integrated circuits are often called system-on-chip (SoC) integrated circuits and can include multiple processors, multiple memories, multiple peripheral devices, and the like. With such system-on-chip integrated circuits the communication circuitry provided fulfils an important role in permitting the required data transfers within the integrated circuit to be efficiently performed.
It is known within the field of data processing to use data compression techniques such as runlength coding. Runlength coding can be particularly useful to compress data such as image data in which significant portions of the data share a common value, e.g. an image may contain large areas with a common pixel value thereby permitting adjacent pixel values to be represented as a run of pixel values with that common pixel value.